Candidate: During Dr. Finder s training in pediatric pulmonary at the Massachusetts General Hospital. He investigated epithelial cell biology and transcription factors involved in cell growth under the supervision of Drs. Daniel Shannon and Louis Ercolani. At the University of Pittsburgh, where Dr. Finder is an attending pediatric pulmonologist, he has spent two years working with Drs. Paul Davies and Bruce Pitt. Recently Ras signaling expertise from Dr. Sebti s laboratory in the Department of Pharmacology has allowed Dr. Finder to initiate the present project investigating the role of Ras in IL-1B induction of iNOS. This five year period will provide him adequate time to develop as an independent biomedical investigator, a goal to which he is firmly committed. Research: Sepsis is a condition characterized by high circulating levels of interleukins and other cytokines. IL-1B is one such cytokine elevated in sepsis and is a potent inducer of nitric oxide synthase (NOS), among other stress-response genes. This upregulation of NOS may contribute to the hypotension characteristic of sepsis. The applicant s long term objective is to undertake studies that will enhance our understanding of how IL-1B induces nitric oxide synthase. The hypothesis upon which this proposal is based is that IL-1B activates (directly or indirectly) the Ras-MAP kinase pathway which ultimately leads to activation of iNOS. The specific aims of this proposal are: A. To determine the effects of Ras tetrapeptide mimetics that inhibit Ras function on IL-1B induction of NOS expression in pulmonary artery smooth muscle cells (PASMC). Other effects of the inhibitors on downstream signaling events (nuclear translocation of NF-kB, activation of MAP kinase, Raf-1, and Ras activation) will also be evaluated. B. To determine whether mutants of Ras that are constitutively activated (GTP-locked) can induce NOS expression and whether inhibitors of Ras function can antagonize this NOS induction. The role of Ras in NOS induction will also be evaluated by determining the effect of dominant negative mutants of Ras on IL-1B induction of NOS. C. To determine in a mouse model the ability of Ras inhibitors to block endotoxin induced expression of NOS. The above studies are designed to enhance our understanding of the role of small G-proteins in mediating pathological conditions such as sepsis. Results from this proposal will potentially lead to effective therapeutic strategies for management of septic shock and pulmonary hypertension. Environment: The University of Pittsburgh is an ideal site for fostering new investigators because of its clinical and scientific excellence. Its research facility, the Biomedical Science Tower, is a vast resource, allowing cross fertilization with numerous disciplines. The adjacent laboratories of Drs. Sebti, Davies and Pitt are extremely favorable for this project because of their work in the investigation of small G proteins, signal transduction, gene transfer, and pulmonary vascular physiology.